The present invention relates to robotic manipulator devices for effecting motion of associated tooling from one position to another. More specifically, the present invention relates to a process and apparatus for imparting linear motion of associated tooling from one position to another.
Robotic manipulator devices are used in industry to perform operations such as welding, assembling parts, material handling, deburring, palletizing, and the like. Typically, the robotic manipulator devices perform the above operations repetitively on a number of identical workpieces. Various types of tooling are coupled to the end of the manipulator devices to perform the desired operations described above.
Robotic manipulator devices having first and second arms of equal lengths are known in the art. Pivotable movement of the first arm is effected by a first motor and pivotable movement of the second arm, which is pivotally connected to the first arm, is effected by a second motor. A tool or workpiece holder is coupled to the distal end of the second arm. Oftentimes it is desirable to move the tool or workpiece holder along a linear path. For example, it may be required to move a workpiece along a straight-line path to load it within a workpiece holder. Movement of the tool or workpiece along a linear path can typically be accomplished by driving the two motors at generally the same speed, assuming the gearing used to transfer rotational motion from the first motor to the first arm is of the same ratio as the gearing used to transfer rotational motion from the second motor to the second arm.
Such a manipulator is oftentimes sufficient for performing most functions. However, if the manipulator is intended to be used in a work space or an enclosure having a vertical dimension which differs substantially from a horizontal dimension, it may contact one of the walls defining the work space or the enclosure as it moves to either its retracted-most position or its extended-most position. For example, if the enclosure has a horizontal dimension which is greater than the vertical dimension, the first arm may contact the upper-most wall of the enclosure when the device is moved to its retracted-most position.
It would be desirable to have a robotic manipulator device comprising first and second arms which is capable of moving within an enclosure having a horizontal dimension which differs from the vertical dimension and which is capable of moving along a straight-line path.